Touch panel and display device

ABSTRACT

Provided is an electrostatic capacitance type touch panel, wherein lead lines are connected to respective end portions of at least either one of the X electrodes and the Y electrodes respectively, the touch panel further comprises an inspection electrode which is laminated to respective end portions of the at least either one of the X electrodes and the Y electrodes with an insulation film sandwiched therebetween on a side where the lead lines are not connected to the at least either one of the X electrodes and the Y electrodes, and a voltage for inspection is supplied to the inspection electrode during an inspection time and a voltage at the same phase as the drive voltage supplied to the at least either one of the X electrodes and the Y electrodes is supplied to the inspection electrode during a usual operation time.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority from Japanese application JP2010-097491 filed on Apr. 21, 2010, the content of which is herebyincorporated by reference into this application.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a touch panel and a display device, andmore particularly to a technique which is effectively applicable innarrowing a width of a picture frame region outside an effective touchregion.

2. Description of the Related Art

A display device which is provided with a device for inputtinginformation with a touch operation using a finger of a user or a pen(contact pushing operation, hereinafter simply referred to as “touch”)on a display screen (hereinafter also referred to as a touch sensor or atouch panel) is used in a mobile electronic device such as a PDA or aportable terminal, various household appliances, an automated tellermachine and the like.

As such a touch panel, a resistance-film type touch panel in which achange in a resistance value of a touched portion is detected, anelectrostatic-capacitance type touch panel in which a change incapacitance is detected, an optical-sensor type touch panel in which achange in quantity of light is detected and the like are known.

The electrostatic-capacitance type touch panel has the followingadvantages compared with the resistance-film type touch panel and theoptical-sensor type touch panel. For example, theelectrostatic-capacitance type touch panel is advantageous with respectto a point that transmissivity is high, that is, approximately 90% thuspreventing the lowering of quality of a display image compared to theresistance-film type touch panel and the optical-sensor type touch panelwhere transmissivity is low, that is, approximately 80%. Further,although the resistance-film type touch panel detects a touch positionin response to a mechanical contact with a resistance film and hence,there exists a possibility that the resistance film is deteriorated orbroken, there is no mechanical contact which brings an electrode fordetection into contact with other electrode or the like in theelectrostatic-capacitance type touch panel and hence, theelectrostatic-capacitance type touch panel is advantageous also from aviewpoint of durability.

As the electrostatic-capacitance type touch panel, for example, therehas been known a touch panel of this type disclosed in JP 2008-310550 A.In the touch panel of this type disclosed in the patent document, thetouch panel is provided with electrodes arranged in the longitudinaldirection for detection (hereinafter referred to as X electrodes) andelectrodes arranged in the lateral direction for detection (hereinafterreferred to as Y electrodes) which are arranged in a matrix array in twodimensional directions consisting of the longitudinal direction and thelateral direction, and an input processing part which detects acapacitance of each electrode. When a conductive body such as a fingeris brought into contact with a surface of the touch panel, thecapacitance of each electrode is increased and hence, the inputprocessing part detects the increase of the capacitance, and calculatesinput coordinates based on a signal indicative of a change incapacitance detected by each electrode.

In the electrostatic-capacitance type touch panel disclosed in JP2008-310550 A, lines are led out from one side of the Y electrodes(hereinafter these lines being referred to as lead lines), and the leadlines are connected to terminals which are connected to a flexibleprinted circuit board so that a drive voltage is supplied to the Yelectrodes from one side of the Y electrodes. The touch panel adoptingsuch a method is referred to as a touch panel of one-sided feeding type.

In this touch panel of one-sided feeding type, when disconnection orincrease of resistance occurs in the X electrode, in the Y electrode orthe lead lines of these electrodes, there has been a drawback that aninspection of the disconnection or the increase of resistance withrespect to a panel unit body is difficult.

SUMMARY OF THE INVENTION

The present invention has been made to overcome the above-mentionedproblems of the related art, and it is an object of the presentinvention to provide a technique which can detect disconnection orincrease of resistance of an electrode for detection in a touch panelwhere electricity is supplied from one side of electrodes for detection.

The above-mentioned and other objects and novel technical features ofthe present invention will become apparent from the description of thisspecification and attached drawings.

To briefly explain the summary of representative inventions among theinventions described in this specification, there are as follows.

According to one aspect of the present invention, there is provided anelectrostatic capacitance type touch panel which includes: a substrate;a plurality of X electrodes which are formed over the substrate, theplurality of X electrodes extending in a second direction and beingarranged in a first direction which intersects with the seconddirection; and a plurality of Y electrodes which are formed over thesubstrate, the plurality of Y electrodes extending in the firstdirection while intersecting the X electrodes and being arranged in thesecond direction; a drive voltage being supplied to the plurality of Yelectrodes from one side of the plurality of Y electrodes, wherein leadlines are connected to respective end portions of at least either one ofthe X electrodes and the Y electrodes respectively, the touch panelfurther includes an inspection electrode which is laminated torespective end portions of the at least either one of the X electrodesand the Y electrodes with an insulation film sandwiched therebetween ona side where the lead lines are not connected to the at least either oneof the X electrodes and the Y electrodes, and a voltage for inspectionis supplied to the inspection electrode during an inspection time and avoltage at the same phase as the drive voltage supplied to the at leasteither one of the X electrodes and the Y electrodes is supplied to theinspection electrode during a usual operation time.

According to another aspect of the present invention, there is providedan electrostatic capacitance type touch panel which includes: asubstrate; a plurality of X electrodes which are formed over thesubstrate, the plurality of X electrodes extending in a second directionand being arranged in a first direction which intersects with the seconddirection; and a plurality of Y electrodes which are formed over thesubstrate, the plurality of Y electrodes extending in the firstdirection while intersecting the X electrodes and being arranged in thesecond direction; a drive voltage being supplied to the plurality of Yelectrodes from one side of the plurality of Y electrodes, wherein leadlines are connected to respective end portions of at least either one ofthe X electrodes and the Y electrodes respectively, the at least eitherone of the X electrodes and the Y electrodes is divided into first andsecond groups, and the lead lines which are connected to the respectiveend portions of the at least either one of the X electrodes and the Yelectrodes in the first group and the lead lines which are connected tothe respective end portions of the at least either one of the Xelectrodes and the Y electrodes in the second group are led out indirections different from each other, the touch panel further includes afirst inspection electrode which is laminated to respective end portionsof the at least either one of the X electrodes and the Y electrodes inthe first group on a side where the lead lines are not connected to theat least either one of the X electrodes and the Y electrodes with aninsulation film sandwiched therebetween, and a second inspectionelectrode which is laminated to respective end portions of the at leasteither one of the X electrodes and the Y electrodes in the second groupon a side where the lead lines are not connected to the at least eitherone of the X electrodes and the Y electrodes with an insulation filmsandwiched therebetween, and a voltage for inspection is supplied to thefirst inspection electrode and the second inspection electrode during aninspection time and a voltage at the same phase as the drive voltagesupplied to the Y electrodes is supplied to the first inspectionelectrode and the second inspection electrode during a usual operationtime.

To briefly explain advantageous effects acquired by the representativeinventions among the inventions described in this specification, it isas follows.

According to the present invention, disconnection or increase ofresistance of an electrode for detection can be detected in a touchpanel where electricity is supplied from one side of electrodes fordetection.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view for explaining a touch panel according to an embodiment1 of the present invention;

FIG. 2 is a cross-sectional view of an essential part showing thecross-sectional structure of the touch panel taken along a line II-II inFIG. 1;

FIG. 3 is a cross-sectional view of an essential part showing thecross-sectional structure of the touch panel taken along a line III-IIIin FIG. 1;

FIG. 4 is a view for explaining a touch panel according to amodification of the embodiment 1 of the present invention;

FIG. 5 is a cross-sectional view of an essential part showing thecross-sectional structure of the touch panel taken along a line V-V inFIG. 4;

FIG. 6 is a cross-sectional view of an essential part showing thecross-sectional structure of the touch panel taken along a line VI-VI inFIG. 4;

FIG. 7 is a view for explaining a touch panel according to an embodiment2 of the present invention;

FIG. 8 is a view for explaining a touch panel according to amodification of the embodiment 2 of the present invention;

FIG. 9 is a cross-sectional view of an essential part showing thecross-sectional structure of the touch panel taken along a line IX-IX inFIG. 8;

FIG. 10 is a cross-sectional view of an essential part showing thecross-sectional structure of the touch panel taken along a line X-X inFIG. 8;

FIG. 11 is a view for explaining a touch panel according to anembodiment 3 of the present invention;

FIG. 12 is a view for explaining an X electrode of a touch panelaccording to an embodiment 4 of the present invention;

FIG. 13 is a view for explaining an X electrode of a touch panelaccording to an embodiment 5 of the present invention;

FIG. 14 is a view for explaining a drawback of the touch panel accordingto the embodiment 4 of the present invention;

FIG. 15 is a view for explaining an X electrode of a touch panelaccording to an embodiment 6 of the present invention; and

FIG. 16 is a view for explaining lead lines of a touch panel accordingto an embodiment 7 of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the present invention are explained in detail inconjunction with drawings hereinafter.

In all drawings for explaining the embodiments, parts having identicalfunctions are given same symbols, and the repeated explanation of theseparts is omitted. Further, the embodiments explained hereinafter are notused for limiting the interpretation of claims of the present invention.

Embodiment 1

FIG. 1 is a view for explaining a touch panel according to theembodiment 1 of the present invention, FIG. 2 is a cross-sectional viewof an essential part showing the cross-sectional structure taken along aline II-II in FIG. 1, and FIG. 3 is a cross-sectional view of anessential part showing the cross-sectional structure taken along a lineIII-III in FIG. 1.

As shown in FIG. 1, the touch panel of this embodiment includes aplurality of X electrodes (X1 to X4) which extend in a second direction(Y direction) and are arranged parallel to each other in a firstdirection (X direction) which intersects with the second direction at apredetermined arrangement pitch, and a plurality of Y electrodes (Y1 toY6) which extend in the first direction intersecting with the Xelectrodes and are arranged parallel to each other in the seconddirection at a predetermined arrangement pitch. A portion indicated by adotted frame in FIG. 1 indicates an effective touch region.

Each one of the plurality of X electrodes has an electrode pattern inwhich a fine line portion 1 a and a pad portion 1 b having a widthlarger than a width of the fine line portion 1 a are arrangedalternately in the second direction.

As shown in FIG. 2 and FIG. 3, the plurality of X electrodes arearranged on an insulation film 12, and a protective film 13 is formedover the plurality of X electrodes.

Each Y electrode has an electrode pattern in which a fine line portion 2a and a pad portion 2 b having a width larger than a width of the fineline portion 2 a are arranged alternately in the first direction inplural number.

As viewed in a plan view, the pad portions 1 b of each X electrode andthe pad portions 2 b of each Y electrode are arranged not to overlapwith each other, and the fine line portion 1 a of each X electrode andthe fine line portion 2 a of each Y electrode intersect with each other.

As shown in FIG. 2 and FIG. 3, the respective fine line portions 2 a ofthe plurality of Y electrodes are formed over a layer different from alayer on which the fine line portions 1 a and the pad portions 1 b ofthe X electrodes are formed, and the fine line portions 2 a of the Yelectrodes intersect with the fine line portions 1 a of the X electrodesas viewed in a plan view. The respective pad portions 2 b of theplurality of Y electrodes are formed over the same layer as the fineline portions 1 a and the pad portions 1 b of the X electrodes in aseparated manner from the pad portions 1 b of the X electrodes. In thisembodiment, the fine line portions 1 a of the X electrodes are formedabove the fine line portions 2 a of the Y electrodes.

The respective pad portions 2 b of the plurality of Y electrodes arecovered with the protective film 13. The fine line portion 2 a of the Yelectrode is formed over a substrate 11, and the fine line portion 2 aof the Y electrode is electrically connected with two pad portions 2 barranged adjacent to each other with the fine line portion 2 asandwiched therebetween via a contact hole 12 a formed in the insulationfilm 12. A transparent insulating substrate made of glass or the like,for example, is used as the substrate 11. The X electrodes and the Yelectrodes are formed using a material which possesses hightransmissivity, for example, a transparent conductive material such asITO (Indium Tin Oxide), for example.

The touch panel of this embodiment is also a touch panel of a one-sidedfeeding type. As shown in FIG. 1, the X electrodes are constituted offour X electrodes X1 to X4, the respective X electrodes are connected tolead lines (LX1 to LX4), and the lead lines (LX1 to LX4) are connectedto respective terminal portions (TX1 to TX4) formed on one side of thesubstrate 11.

The Y electrodes are constituted of six Y electrodes Y1 to Y6, one-endportions of the respective Y electrodes are connected to lead lines (LY1to LY6), and the lead lines (LY1 to LY6) are connected to respectiveterminal portions (TY1 to TY6) formed over one side of the substrate 11.Further, the other-end portions of the Y electrodes are respectivelyconnected to inspection portions (PY1 to PY6). The lead lines (LX1 toLX4, LY1 to LY6) and the inspection portions (PY1 to PY6) are formed inregions outside the effective touch region (a region indicated by anarrow A in FIG. 2), and are formed of a metal layer such as a silveralloy film.

As shown in FIG. 1, in this embodiment, the inspection portions (PY1 toPY6) are formed in a region on a side opposite to the region where thelead lines (LY1 to LY6) of the Y electrodes are formed. An inspectionelectrode KY is formed over a lower side of the inspection portions (PY1to PY6). The inspection electrode KY is connected to a terminal portionTKY which is formed on one side of the substrate 11.

In this manner, according to this embodiment, the inspection portions(PY1 to PY6) and the inspection electrode KY are arranged to face eachother with the insulation film 12 sandwiched therebetween. That is,capacitance is generated between the inspection electrode KY and theinspection portions (PY1 to PY6).

The inspection portions (PY1 to PY6) are formed over the same layer asthe fine line portions 1 a and the pad portions 1 b of the X electrodesand the pad portions 2 b of the Y electrodes, and are formed of atransparent conductive film such as ITO in the same manner as the Xelectrodes and the Y electrodes.

The inspection electrode KY is formed over the substrate 11 using atransparent conductive material such as ITO (Indium Tin Oxide), forexample, or is formed of a metal layer such as a silver alloy film, forexample.

In the touch panel, to allow the detection of a change in capacitance ofeach electrode by a finger touch, it is necessary that the X electrodesand the Y electrodes are surely connected to the terminal portionsformed on one side of the substrate by the respective lead lines. When adisconnection or increase of resistance exists on a certain electrode orin the midst of a certain lead line, the detection of capacitance by thefinger touch cannot be performed.

In this embodiment, at the time of manufacturing a product, a voltagehaving a rectangular waveform is inputted to the inspection electrode KYfrom the terminal portion TKY. Then, the voltage having a rectangularwaveform inputted to the inspection electrode KY is inputted to therespective Y electrodes (Y1 to Y6) via capacitances generated betweenthe inspection electrode KY and the inspection portions (PY1 to PY6). Byobserving the voltages having a rectangular waveform inputted to the Yelectrodes (Y1 to Y6) at the respective terminal portions (TY1 to TY6),a disconnection or increase of resistance in the Y electrodes (Y1 to Y6)and the lead lines (LY1 to LY6) can be detected.

Accordingly, in this embodiment, at the time of manufacturing a product,a disconnection or increase of resistance of the Y electrodes (Y1 to Y6)and the lead lines (LY1 to LY6) can be detected, and a touch panel inwhich the disconnection or the increase of resistance is recognized canbe excluded as a defective product thus realizing touch panels whichexhibit a high yield at the time of manufacturing products.

In a usual operation, a voltage equal to a drive voltage supplied to theY electrodes (Y1 to Y6) is supplied to the inspection electrode KY.Accordingly, capacitive coupling between the inspection portions (PY1 toPY6) and the inspection electrode KY can be suppressed.

For example, when a user touches a surface of the touch panel on the Yelectrode Y6 with his finger, a change in capacitance is generated onthe Y electrode Y6 by the finger touch. A touch panel controller detectsthis change in capacitance, and determines that the finger touch is madeon the Y electrode Y6.

In such a case, assuming that a cross talk is generated between the Yelectrode Y6 and the Y electrode Y5 via the inspection electrode KY, thetouch panel controller detects that a capacitance on the Y electrode Y5is also slightly changed. Accordingly, the touch panel controllererroneously determines that the finger touch is made between the Yelectrode Y5 and the Y electrode Y6.

In this manner, when the cross talk is generated, the touch panelcontroller determines a position displaced from a position at which thefinger touch is made and hence, the accuracy in position determinationis deteriorated.

Accordingly, by supplying a voltage equal to a drive voltage supplied tothe Y electrodes (Y1 to Y6) to the inspection electrode KY, capacitivecoupling between the inspection portions (PY1 to PY6) and the inspectionelectrode KY can be canceled in appearance and hence, theabove-mentioned cross talk can be suppressed whereby the touch panelwhich exhibits high accuracy in position determination can be realized.

[Touch Panel According to Modification of Embodiment 1]

FIG. 4 is a view for explaining a touch panel according to amodification of the embodiment 1 of the present invention, FIG. 5 is across-sectional view of an essential part showing the cross-sectionalstructure taken along a line V-V in FIG. 4, and FIG. 6 is across-sectional view of an essential part showing the cross-sectionalstructure taken along a line VI-VI in FIG. 4.

In the touch panel shown in FIG. 4 to FIG. 6, as viewed in a plan view,pad portions 1 b of respective X electrodes and pad portions 2 b ofrespective Y electrodes are arranged without overlapping with eachother, and fine line portions 1 a of the respective X electrodes andfine line portions 2 a of the respective Y electrodes intersect witheach other.

The fine line portions 2 a of the plurality of Y electrodes and the fineline portions 1 a and the pad portions 1 b of the plurality of Xelectrodes are formed over layers different from each other. The padportions 2 b of the plurality of Y electrodes are formed over the samelayer as the fine line portions 1 a and the pad portions 1 b of the Xelectrodes, but are formed separate from the pad portions 1 b of the Xelectrodes. The fine line portions 1 a and the pad portions 1 b of theplurality of X electrodes, and the pad portions 2 b of the plurality ofY electrodes are formed over a substrate 11 and are covered with aninsulation film 12.

The fine line portions 2 a of the plurality of Y electrodes are formedover the insulation film 12 formed above the fine line portions 1 a ofthe X electrodes, and each fine line portion 2 a of the plurality of Yelectrodes is electrically connected with two pad portions 2 b arrangedadjacent to each other with the fine line portion 2 a sandwichedtherebetween via a contact hole 12 a formed in the insulation film 12.The respective fine line portions 2 a of the plurality of Y electrodesare covered with a protective film 13.

In the touch panel shown in FIG. 4 to FIG. 6, the Y electrodes areformed over the substrate 11. Accordingly, inspection portions (PY1 toPY6) are also formed over the substrate 11 and hence, an inspectionelectrode KY is formed over the insulation film 12 in the same manner asthe fine line portions 2 a of the plurality of Y electrodes.

Also in the touch panel shown in FIG. 4 to FIG. 6, the inspectionportions (PY1 to PY6), the X electrodes and the Y electrodes are formedusing a transparent conductive film such as ITO. Further, the inspectionelectrode KY is formed using a transparent conductive material such asIndium Tin Oxide (ITO), for example, or is formed of a metal layer suchas a silver alloy film, for example.

Embodiment 2

FIG. 7 is a view for explaining a touch panel according to an embodiment2 of the present invention.

This embodiment is characterized that inspection portions (PX1 to PX4)are also formed over X electrodes X1 to X4, and an inspection electrodeKX is formed in such a manner that an insulation layer is sandwichedbetween the inspection electrode KX and the inspection portions (PX1 toPX4). The inspection electrode KX is connected to a terminal portion(not shown in the drawing) which is formed on one side of a substrate11. That is, this embodiment is provided for detecting a disconnectionor increase of resistance of the X electrodes (X1 to X4) and lead lines(LX1 to LX4).

Also in this embodiment, the inspection portions (PX1 to PX4) are formedover the same layer as fine line portions 1 a and pad portions 1 b ofthe X electrodes and pad portions 2 b of Y electrodes in an effectivetouch region, and are formed of a transparent conductive film such asITO in the same manner as the X electrodes and the Y electrodes.

The inspection electrode KX is formed using a transparent conductivematerial such as ITO (Indium Tin Oxide), for example, or is formed of ametal layer such as a silver alloy film, for example.

When the structure of the touch panel of this embodiment adopts thestructure shown in FIG. 1 to FIG. 3, the inspection portions (PX1 toPX4) are arranged on an insulation film 12, and the inspection electrodeKX is formed over the substrate 11. Further, when the structure of thetouch panel according to this embodiment adopts the structure shown inFIG. 4 to FIG. 6, the inspection portions (PX1 to PX4) are formed overthe substrate 11 and the inspection electrode KX is formed over theinsulation film 12.

At the time of manufacturing a product, a voltage having a rectangularwaveform is inputted to the inspection electrode KX from a terminalportion TKX. Then, the voltage having a rectangular waveform inputted tothe inspection electrode KX is inputted to the respective X electrodes(X1 to X4) via capacitances generated between the inspection electrodeKX and the inspection portions (PX1 to PX4). By observing the voltageshaving a rectangular waveform inputted to the X electrodes (X1 to X4) atrespective terminal portions (TX1 to TX4), a disconnection or increaseof resistance in the X electrodes (X1 to X4) and the lead lines (LX1 toLX4) can be detected.

Accordingly, also in this embodiment, at the time of manufacturing aproduct, the disconnection or the increase of resistance of the Xelectrodes (X1 to X4) and the lead lines (LX1 to LX4) and thedisconnection or the increase of resistance of the Y electrodes (Y1 toY6) and lead lines (LY1 to LY6) can be detected, and a touch panel inwhich the disconnection or the increase of resistance is recognized canbe excluded as a defective product thus realizing touch panels whichexhibit a high yield at the time of manufacturing products.

In a usual operation, a voltage equal to a drive voltage supplied to theX electrodes (X1 to X4) is supplied to the inspection electrode KX.Accordingly, capacitive coupling between the inspection portions (PX1 toPX4) and the inspection electrode KY can be suppressed.

[Another Example of Specific Electrode Structure of Touch PanelAccording to Embodiment 2]

FIG. 8 is a view for explaining a touch panel according to amodification of the embodiment 2 of the present invention, FIG. 9 is across-sectional view of an essential part showing the cross-sectionalstructure taken along a line IX-IX in FIG. 8, and FIG. 10 is across-sectional view of an essential part showing the cross-sectionalstructure taken along a line X-X in FIG. 8.

Also in the touch panel shown in FIG. 8 to FIG. 10, as viewed in a planview, pad portions 1 b of respective X electrodes and pad portions 2 bof respective Y electrodes are arranged without overlapping with eachother, and fine line portions 1 a of the respective X electrodes andfine line portions 2 a of the respective Y electrodes intersect witheach other.

The touch panel shown in FIG. 8 to FIG. 10 is characterized in that theX electrodes and the Y electrodes are formed over different layers withan insulation film 12 sandwiched therebetween as shown in FIG. 8 to FIG.10, wherein the X electrodes are formed below the Y electrodes and areformed over a viewer's side surface of a glass substrate 11.

In the touch panel shown in FIG. 8 to FIG. 10, inspection portions (PX1to PX4) on an X electrode side are formed over the substrate 11, andinspection portions (PY1 to PY6) on a Y electrode side are formed overthe insulation film 12. Accordingly, inspection electrodes KX, KY may beformed over an intermediate layer between the X electrodes and the Yelectrodes.

Embodiment 3

FIG. 11 is a view for explaining a touch panel according to anembodiment 3 of the present invention.

This embodiment is characterized in that, in the touch panel of theabove-mentioned embodiment 1, the Y electrodes Y1 to Y6 are divided intotwo groups of Y electrodes, that is, the Y electrodes Y1 to Y3 and the Yelectrodes Y4 to Y6, and the lead lines (LY1 to LY3) for the Yelectrodes Y1 to Y3 and the lead lines (LY4 to LY6) for the Y electrodesY4 to Y6 are led out from sides opposite to each other. Accordingly, inthis embodiment, the inspection electrode KY is also divided into twoinspection electrodes KY1, KY2. In this embodiment, a width of a pictureframe region of an effective touch region can be set uniform betweenleft and right sides.

In this embodiment, the X electrodes may be also divided into two groupsof X electrodes and two inspection electrodes KX may be provided for thedivided groups of X electrodes respectively.

In this embodiment, it is desirable that the inspection electrodes (KX,KY) are formed between a layer on which the Y electrodes are formed anda layer on which the X electrodes are formed.

Embodiment 4

FIG. 12 is a view for explaining an X electrode of a touch panelaccording to an embodiment 4 of the present invention. Theelectrostatic-capacitance type touch panel determines the presence orthe non-presence of a finger touch based on a change in capacitance ofan X electrode or a Y electrode by a finger touch. Sensitivity in suchan operation is influenced by capacitances and resistances of the Xelectrode and the Y electrode per se. That is, when the capacitances arelarge, it is impossible to grasp a change in capacitance when a usertouches the touch panel. When the resistances are large, the electrodes(X electrode and Y electrode) cannot be charged sufficiently and hence,a response value for the finger touch becomes small so that sensitivityis lowered.

Further, when the reaction value in response to the finger touchfluctuates within the effective touch region, a region where sensitivityis insufficient is formed partially and such a region adverselyinfluences a manipulation. Particularly, in a touch panel of a one-sidedfeeding type, a line length of electrodes which are arranged parallel toa long side of the touch panel (X electrodes in this embodiment) islarge and hence, there may be a case where a load is increased at aremote end remote from a feeding end thus giving rise to theabove-mentioned phenomenon.

In view of the above, according to this embodiment, to eliminate thedifference in the reaction value in response to the finger touch betweena near end and the remote end, by focusing on a fine line portion 1 awhich connects the electrodes and is largely relevant to a resistancevalue, as shown in FIG. 12, a width of the fine line portion 1 a isincreased along with the increase of a distance from the feeding endsuch that a width of a fine line portion 1 af at the remotest end is settwice or more as large as a width of a fine line portion 1 an at thenearest end near the feeding end (B≧2×A in FIG. 12). Accordingly, thereaction value in response to the finger touch can be made uniformbetween a remote end side remote from the feeding end and a near endside near the feeding end.

In the above-mentioned embodiment, the width of the fine line portion 1a is increased along with the increase of the distance from the feedingend such that the width of the fine line portion 1 a at the remotest endis set twice or more as large as the width of the fine line portion 1 anat the nearest end near the feeding end (B≧2×A in FIG. 12) with respectto the fine line portion 1 a of the X electrode. However, also withrespect to a fine line portion 2 a of the Y electrode, a width of thefine line portion 2 a may be increased along with the increase of adistance from a feeding end such that a width of the fine line portion 2a at the remotest end is set twice as large as a width of the fine lineportion 2 a at the nearest end near the feeding end.

Embodiment 5

FIG. 13 is a view for explaining an X electrode of a touch panelaccording to an embodiment 5 of the present invention.

In this embodiment, as shown in FIG. 13, in the X electrode, compared toa size (or an area) of a pad portion 1 bn on a near end side nearest toa feeding end, a size (or an area) of a pad portion 1 bf on a remote endside remotest from the feeding end is set small, and floating electrodes1 c are added to the pad portion 1 bf.

Due to such a constitution, a charge time can be shortened and aninter-electrode capacitance can be decreased and hence, a reaction valueof the pad portion 1 bf remotest from the feeding end in response to atouch on the X electrode can be enhanced.

In the above-mentioned embodiment, the size (or the area) of the padportion 1 bf on the remote end side from the feeding end is set smalland the floating electrodes 1 c are added to the pad portion 1 bf withrespect to the X electrode. However, a size (or an area) of a padportion 2 b on a remote end side remote from a feeding end may be setsmall and floating electrodes 1 c may be added to the pad portion 2 bwith respect to a Y electrode.

Although the size (or the area) of a pad portion 1 b (or the pad portion2 b) on the remote end side remotest from the feeding end is set smalland the floating electrodes 1 c are added to the pad portion 1 b (or thepad portion 2 b) with respect to the X electrode (or the Y electrode) inthis embodiment, a plurality of pad portions 1 b (or pad portions 2 b)on the remote end side remote from the feeding end may be set small insize (or area) and the floating electrodes 1 c may be added to the padportions 1 b (or the pad portions 2 b) in the X electrode (or the Yelectrode). In this case, the number of the pad portions 1 b (or the padportions 2 b) whose size (or area) is decreased and to which thefloating electrodes 1 c are added may be set such that a reaction valuein response to a finger touch can be made uniform in the X electrode (orthe Y electrode). Further, sizes (or areas) of the pad portions 1 b (orthe pad portions 2 b) of the X electrode (or the Y electrode) may begradually decreased along with the increase of a distance from thefeeding end, and sizes (or areas) of the floating electrodes 1 c may begradually increased along with the increase of the distance from thefeeding end.

Further, by adding the constitution of this embodiment to theconstitution of the previously-mentioned embodiment 4, a reaction valueof the pad portion 1 bf remotest from the feeding end in response to atouch can be enhanced. FIG. 13 shows such a constitution.

Embodiment 6

In the electrode structure of the previously-mentioned embodiment 4, thewidth of the fine line portion 1 a of the X electrode is increased alongwith the increase of the distance from the feeding end. Accordingly, asshown in FIG. 14, an area of the pad portion 2 b of the Y electrodehaving the fine line portion 2 a which intersects with the fine lineportion 1 a of the X electrode remotest from the feeding end is alsodecreased. FIG. 14 is a view for explaining a drawback of the touchpanel according to the embodiment 4 of the present invention.

FIG. 15 is a view for explaining an X electrode of a touch panelaccording to an embodiment 6 of the present invention.

This embodiment is, as shown in FIG. 15, characterized in that theresistance of a fine line portion 1 a of an X electrode remotest from afeeding end is lowered by laminating a metal layer MT to the fine lineportion 1 a. Due to such a constitution, compared to thepreviously-mentioned embodiment 4 shown in FIG. 12, a line width of thefine line portion 1 a of the X electrode remotest from the feeding endcan be made small and hence, it is possible to make the X electrodes andY electrodes more difficult to be recognized by a user. Further, a sizeof the X electrode and a size of the Y electrode can be made uniformwith each other and hence, linearity of the electrodes can be enhanced.

In the above-mentioned embodiment, although the resistance of the fineline portion 1 a of the X electrode remotest from the feeding end islowered by laminating the metal layer MT to the fine line portion 1 a,the resistance of a fine line portion 2 a of the Y electrode remotestfrom a feeding end may be lowered by laminating the metal layer MT tothe fine line portion 2 a.

In this embodiment, in place of lowering the resistance of the fine lineportion 1 a (or the fine line portion 2 a) remotest from the feeding endby laminating the metal layer MT to the fine line portion 1 a (or thefine line portion 2 a) with respect to the X electrode (or the Yelectrode), the resistance of the fine line portion 1 a (or the fineline portion 2 a) remotest from the feeding end may be lowered byincreasing a film thickness of the fine line portion 1 a (or the fineline portion 2 a) remotest from the feeding end with respect to the Xelectrode (or the Y electrode). Also in this case, it is possible tomake the X electrodes and the Y electrodes more difficult to berecognized by the user. Further, a size of the X electrode and a size ofthe Y electrode can be made uniform with each other and hence, linearityof the electrodes can be enhanced.

In FIG. 15, the metal layer MT is laminated to the fine line portion 1 a(or the fine line portion 2 a) remotest from the feeding end) withrespect to the X electrode (or the Y electrode). However, the metallayer MT may be laminated to a plurality of the fine line portions 1 a(or the fine line portions 2 a) on a remote side remote from the feedingend in the X electrode (or Y electrode). In this case, the number of thefine line portions 1 a (or the fine line portions 2 a) on which themetal layer MT is laminated may be set such that a size of the Xelectrode and a size of the Y electrode become uniform.

Further, this embodiment is also applicable to a usual touch panel, thatis, a touch panel where fine line portions 1 a (or the fine lineportions 2 a) of the X electrodes (or the Y electrodes) have a uniformwidth.

Embodiment 7

FIG. 16 is a view for explaining lead lines of a touch panel accordingto an embodiment 7 of the present invention.

As shown in FIG. 16, this embodiment is characterized in that, the leadlines (LX1 to LX4, LY1 to LY6) are connected to resistances (R1) of100kΩ or more so as to prevent the appearance of irregularities inresistance value among X electrodes or irregularities in resistancevalue among Y electrodes within an effective touch region thus making areaction value in response to a touch uniform within the effective touchregion. Further, this embodiment can also cope with noises effectively.

In the touch panels of the above-mentioned embodiments 1 to 3, shapes ofthe pad portion 1 b of the X electrode and the pad portion 2 b of the Yelectrode in a peripheral portion of the touch panel are set half ofshapes of the pad portions in a center portion. As described previously,one of causes which bring about the fluctuation of a reaction value inresponse to a finger touch is that a load is increased at the remote endremote from the feeding end. In this respect, in the touch panels of theembodiments 1 to 3, the pad portions (1 b, 2 b) of the X electrode andthe Y electrode remotest from the feeding end are set half of the padportions in the center portion in shape and hence, the load is alsohalved approximately. Accordingly, the fine line portions (1 a, 2 a) orthe pad portions (1 b, 2 b) to which the above-mentioned embodiments 4to 7 are applied may be the fine line portions (1 a, 2 a) or the padportions (1 b, 2 b) preceding to the fine line portions (1 a, 2 a) orthe pad portions (1 b, 2 b) of the X electrode and the Y electroderemotest from the feeding end by one.

Further, the above-mentioned embodiments 4 to 7 are also applicable tothe touch panel shown in FIG. 1 to FIG. 3, the touch panel shown in FIG.4 to FIG. 6, and the touch panel shown in FIG. 8 to FIG. 10.

As described previously, the touch panel of the above-mentioned eachembodiment is arranged on a display panel of a liquid crystal displaydevice or an organic EL display device, and is used as a device forinputting information by performing a touch operation on a displayscreen with a finger of a user, a pen or the like.

Although the inventions which are made by inventors of the presentinvention have been specifically explained in conjunction with theembodiments, it is needless to say that the present invention is notlimited to the above-mentioned embodiments and various modifications areconceivable without departing from the gist of the present invention.

1. An electrostatic capacitance type touch panel comprising: asubstrate; a plurality of X electrodes which are formed over thesubstrate, the plurality of X electrodes extending in a second directionand being arranged in a first direction which intersects with the seconddirection; and a plurality of Y electrodes which are formed over thesubstrate, the plurality of Y electrodes extending in the firstdirection while intersecting with the X electrodes and being arranged inthe second direction; a drive voltage being supplied to the plurality ofY electrodes from one side of the plurality of Y electrodes, whereinlead lines are connected to respective one-end portions of at leasteither one of the X electrodes and the Y electrodes respectively, thetouch panel further comprises an inspection electrode which is laminatedto respective end portions of the at least either one of the Xelectrodes and the Y electrodes with an insulation film sandwichedtherebetween on a side where the lead lines are not connected to the atleast either one of the X electrodes and the Y electrodes, and a voltagefor inspection is supplied to the inspection electrode during aninspection time and a voltage at the same phase as the drive voltagesupplied to the at least either one of the X electrodes and the Yelectrodes is supplied to the inspection electrode during a usualoperation time.
 2. The touch panel according to claim 1, whereininspection portions which are connected to the at least either one ofthe X electrodes and the Y electrodes are formed over the respective endportions of the at least either one of the X electrodes and the Yelectrodes on the side where the lead lines are not connected to the atleast either one of the X electrodes and the Y electrodes respectively,and the inspection portions which are connected to the at least eitherone of the X electrodes and the Y electrodes are laminated to theinspection electrode with the insulation film sandwiched therebetween.3. The touch panel according to claim 1, wherein the respectiveinspection portions which are connected to the at least either one ofthe X electrodes and the Y electrodes, and the inspection electrode areformed outside an effective touch region.
 4. The touch panel accordingto claim 1, wherein the respective X electrodes and the respective Yelectrodes are formed by alternately arranging pad portions and fineline portions in an extending direction thereof respectively, the padportions of the respective X electrodes and the pad portions of therespective Y electrodes are arranged without overlapping with each otheras viewed in a plan view, and the fine line portions of the respective Xelectrodes and the fine line portions of the respective Y electrodes areintersect with each other three-dimensionally, the pad portions and thefine line portions of the respective X electrodes and the pad portionsof the respective Y electrodes are formed over the same layer, the fineline portions of the respective Y electrodes are formed below the padportions of the respective Y electrodes, and are connected to the padportions of the respective Y electrodes via contact holes formed in aninsulation film interposed between the pad portions of the respective Yelectrodes and the fine line portions of the respective Y electrodes,and the inspection electrode is formed over the same layer over whichthe fine line portions of the Y electrodes are formed.
 5. The touchpanel according to claim 1, wherein the respective X electrodes and therespective Y electrodes are formed by alternately arranging pad portionsand fine line portions in an extending direction thereof respectively,the pad portions of the respective X electrodes and the pad portions ofthe respective Y electrodes are arranged without overlapping with eachother as viewed in a plan view, and the fine line portions of therespective X electrodes and the fine line portions of the respective Yelectrodes are intersect with each other three-dimensionally, the padportions and the fine line portions of the respective X electrodes andthe pad portions of the respective Y electrodes are formed over the samelayer, the fine line portions of the respective Y electrodes are formedabove the pad portions of the respective Y electrodes, and are connectedto the pad portions of the respective Y electrodes via contact holesformed in an insulation film interposed between the pad portions of therespective Y electrodes and the fine line portions of the respective Yelectrodes, and the inspection electrode is formed over the same layerover which the fine line portions of the Y electrodes are formed.
 6. Thetouch panel according to claim 1, wherein the respective X electrodesand the respective Y electrodes are formed by alternately arranging padportions and fine line portions in an extending direction thereofrespectively, the pad portions of the respective X electrodes and thepad portions of the respective Y electrodes are arranged withoutoverlapping with each other as viewed in a plan view, and the fine lineportions of the respective X electrodes and the fine line portions ofthe respective Y electrodes are intersect with each otherthree-dimensionally, the X electrodes and the Y electrodes are formedover different layers with an insulation film sandwiched therebetween,and the X electrodes are formed below the Y electrodes, and theinspection electrode is formed between the layer over which the Yelectrodes are formed and the layer over which the X electrodes areformed.
 7. A display device comprising: a display panel; and a touchpanel which is arranged on a viewer's side of the display panel, whereinthe touch panel is the touch panel according to claim
 1. 8. Anelectrostatic capacitance type touch panel comprising: a substrate; aplurality of X electrodes which are formed over the substrate, theplurality of X electrodes extending in a second direction and beingarranged in a first direction which intersects with the seconddirection; and a plurality of Y electrodes which are formed over thesubstrate, the plurality of Y electrodes extending in the firstdirection while intersecting with the X electrodes and being arranged inthe second direction; a drive voltage being supplied to the plurality ofY electrodes from one side of the plurality of Y electrodes, whereinlead lines are connected to respective one-end portions of at leasteither one of the X electrodes and the Y electrodes respectively, the atleast either one of the X electrodes and the Y electrodes is dividedinto first and second groups, and the lead lines which are connected tothe respective end portions of the at least either one of the Xelectrodes and the Y electrodes in the first group and the lead lineswhich are connected to the respective end portions of the at leasteither one of the X electrodes and the Y electrodes in the second groupare led out in directions different from each other, the touch panelfurther comprises a first inspection electrode which is laminated torespective end portions of the at least either one of the X electrodesand the Y electrodes in the first group on a side where the lead linesare not connected to the at least either one of the X electrodes and theY electrodes with an insulation film sandwiched therebetween, and asecond inspection electrode which is laminated to respective endportions of the at least either one of the X electrodes and the Yelectrodes in the second group on a side where the lead lines are notconnected to the at least either one of the X electrodes and the Yelectrodes with an insulation film sandwiched therebetween, and avoltage for inspection is supplied to the first inspection electrode andthe second inspection electrode during an inspection time and a voltageat the same phase as the drive voltage supplied to the Y electrodes issupplied to the first inspection electrode and the second inspectionelectrode during a usual operation time.
 9. The touch panel according toclaim 8, wherein inspection portions which are connected to the at leasteither one of the X electrodes and the Y electrodes are formed over therespective end portions of the at least either one of the X electrodesand the Y electrodes on the side where the lead lines are not connectedto the at least either one of the X electrodes and the Y electrodes inthe first group and the respective end portions of the at least eitherone of the X electrodes and the Y electrodes on the side where the leadlines are not connected to the at least either one of the X electrodesand the Y electrodes in the second group respectively, and therespective inspection portions which are connected to the at leasteither one of the X electrodes and the Y electrodes in the first groupand the second group are laminated to the first inspection electrode andthe second inspection electrode with the insulation film sandwichedtherebetween.
 10. The touch panel according to claim 8, wherein, therespective inspection portions which are connected to the at leasteither one of the X electrodes and the Y electrodes in the first groupand the second group, the first inspection electrode and the secondinspection electrode are formed outside an effective touch region. 11.The touch panel according to claim 8, wherein the respective Xelectrodes and the respective Y electrodes are formed by alternatelyarranging pad portions and fine line portions in an extending directionthereof respectively, the pad portions of the respective X electrodesand the pad portions of the respective Y electrodes are arranged withoutoverlapping with each other as viewed in a plan view, and the fine lineportions of the respective X electrodes and the fine line portions ofthe respective Y electrodes are intersect with each otherthree-dimensionally, the pad portions and the fine line portions of therespective X electrodes and the pad portions of the respective Yelectrodes are formed over the same layer, the fine line portions of therespective Y electrodes are formed below the pad portions of therespective Y electrodes, and are connected to the pad portions of therespective Y electrodes via contact holes formed in an insulation filminterposed between the pad portions of the respective Y electrodes andthe fine line portions of the respective Y electrodes, and the firstinspection electrode and the second inspection electrode are formed overthe same layer over which the fine line portions of the Y electrodes areformed.
 12. The touch panel according to claim 8, wherein the respectiveX electrodes and the respective Y electrodes are formed by alternatelyarranging pad portions and fine line portions in an extending directionthereof respectively, the pad portions of the respective X electrodesand the pad portions of the respective Y electrodes are arranged withoutoverlapping with each other as viewed in a plan view, and the fine lineportions of the respective X electrodes and the fine line portions ofthe respective Y electrodes are intersect with each otherthree-dimensionally, the pad portions and the fine line portions of therespective X electrodes and the pad portions of the respective Yelectrodes are formed over the same layer, the fine line portions of therespective Y electrodes are formed above the pad portions of therespective Y electrodes, and are connected to the pad portions of therespective Y electrodes via contact holes formed in an insulation filminterposed between the pad portions of the respective Y electrodes andthe fine line portions of the respective Y electrodes, and the firstinspection electrode and the second inspection electrode are formed overthe same layer over which the fine line portions of the Y electrodes areformed.
 13. The touch panel according to claim 8, wherein the respectiveX electrodes and the respective Y electrodes are formed by alternatelyarranging pad portions and fine line portions in an extending directionthereof respectively, the pad portions of the respective X electrodesand the pad portions of the respective Y electrodes are arranged withoutoverlapping with each other as viewed in a plan view, and the fine lineportions of the respective X electrodes and the fine line portions ofthe respective Y electrodes are intersect with each otherthree-dimensionally, the X electrodes and the Y electrodes are formedover different layers with an insulation film sandwiched therebetween,and the X electrodes are formed below the Y electrodes, and the firstinspection electrode and the second inspection electrode are formedbetween the layer over which the Y electrodes are formed and the layerover which the X electrodes are formed.
 14. A display device comprising:a display panel; and a touch panel which is arranged on a viewer's sideof the display panel, wherein the touch panel is the touch panelaccording to claim 8.